High power microwave petroleum recovery

ABSTRACT

Methods, systems, and devices are described for using high-power microwave radiation to recover oil from an oil shale deposit. Embodiments include a microwave generation system, adapted to generate in situ, high-power microwave radiation. In some embodiments, one or more antennae propagate the microwave radiation into the oil shale deposit. The microwave radiation may heat the oil shale, causing oil to be released. The released oil may then be collected, refined, transported, or otherwise processed.

CROSS REFERENCES

This application claims priority from co-pending U.S. Provisional Patent Application No. 60/018,818, filed Jan. 3, 2008, entitled “HIGH POWER MICROWAVE PETROLEUM RECOVERY” (Attorney Docket No. 026882-000300US), which is hereby incorporated by reference, as if set forth in full in this document, for all purposes. This application is also related to co-pending U.S. Non-Provisional patent application Ser. No. ______, filed concurrently herewith, entitled “HIGH POWER MICROWAVE PETROLEUM REFINEMENT” (Attorney Docket No. 026882-000320US), which is hereby incorporated by reference, as if set forth in full in this document, for all purposes.

The present invention relates to petroleum recovery in general and, in particular, to recovery of petroleum from oil shale underground through in situ heating.

BACKGROUND

Oil shale may typically occur in sedimentary rocks containing solid bituminous material. Some rich deposits may be found underground in the western United States, as kerogen mixed with minerals (e.g., halites, nahacolites, dawsonites, etc.). In some cases, geologically trapped water, combined with water of crystallization in the minerals, may constitute up to 3 percent by weight of the deposits.

The composition of the oil shale may be such that petroleum oil can be released on heating. The heating process may involve heating kerogen trapped within the oil shale until it becomes hot enough to convert (e.g., pyrolyse, decompose, etc.) into shale oil, shale gas, solid residue, and/or other constituents. While the kerogen may be a relatively useless hydrocarbon, the conversion to shale oil will create a hydrocarbon that may be useful as a non-conventional fuel oil. In some cases, the conversion may begin at around 300° C., but may become faster and more complete as the temperature increases (e.g., to 450° C.). Further, some gasification may occur as temperatures continue to rise (e.g., to 575° C.).

There are at least two categories of heating processes relating to where the heating should occur: ex situ and in situ. With ex situ heating, or ground-surface retorting, oil shale may be mined at or below the surface and transported to a retorting facility. In situ heating processes, however, may convert the kerogen through a bore hole while the oil shale is still in the ground, extracting crude oil straight from the oil shale deposit. Some in situ retorting processes, called modified in situ processes (“MIS”), may involve creating a fractured area above the mined area to aid in vapor/gas flow through the deposit.

In situ heating processes may differ in a number of ways. For example, such processes may heat the oil shale deposit using a variety of technologies, including conductive heating, steam, combustion, microwaves, radiofrequency, and others. Further, some processes may heat from the surface, while others may lower heating elements to depths within the deposit. While many of these processes may be effective for extracting crude oil, they may not provide cost effective solutions (e.g., they use a lot of energy per amont extracted) and may be environmentally undesirable (e.g., by causing groundwater pollution or producing toxic by-products).

As such, it may be desirable to provide efficient and effective in situ heating of oil shale deposits.

SUMMARY

Among other things, embodiments of the invention provide systems, devices, and methods for using high-power microwave radiation to recover oil from an oil shale deposit. One embodiment includes a microwave generation system, adapted to generate high-power microwave radiation. A radiation system may be coupled with the microwave generation system. The radiation system may include an antenna for transmitting the radiation into the oil shale deposit, the antenna being located in situ (i.e., within the oil shale deposit). A sheath may be provided to protect the antenna from harmful exposure to the oil shale deposit and released constituents, while being substantially transparent to the microwave frequency. The high-power microwave radiation may heat the oil shale, causing oil to be released. The released oil may then be collected, refined, transported, or otherwise processed.

One set of embodiments provides a method for recovering oil from an oil shale deposit using in situ, high-power, microwave heating. The method includes generating microwave radiation substantially at a microwave frequency (e.g., approximately 2.45 to 2.5 GHz); and transmitting at least a portion of the microwave radiation into the oil shale deposit from an active radiation source located substantially within the oil shale deposit, such that at least a portion of the oil shale deposit heats to a temperature level at which released constituents are released, the released constituents comprising oil.

Another set of embodiments provides a method for recovering oil from an oil reservoir site. The method includes providing an oil collection system; pumping a measured amount of water into the oil reservoir site, wherein the oil reservoir site is underground and comprises oil; generating microwave radiation substantially at a microwave frequency; and transmitting at least a portion of the microwave radiation into the oil reservoir site from a plurality of in situ radiation sources (e.g., in proximity to the oil reservoir site), such that at least a portion of the water heats to a temperature level at which sufficient steam is generated (e.g., at high pressure) to force the oil into the oil collection system. In certain embodiments, at least a portion of the radiation sources includes a klystron and an antenna. In certain of these embodiments, the antenna is protected by an enclosure that is substantially transparent to the microwave radiation.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the present invention may be realized by reference to the following drawings. In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

FIG. 1 shows a simplified system block diagram of an oil recovery system, according to various embodiments of the invention.

FIG. 2 shows a simplified illustration of an oil recovery system, according to various embodiments of the invention.

FIGS. 3A and 3B show illustrations of a front view and a side view of an antenna, respectively, according to various embodiments of the invention.

FIG. 4 shows an illustration of a top view of an oil shale deposit with multiple distributed antennae, according to various embodiments of the invention.

FIG. 5A shows an illustration of a top view of an oil shale deposit with a single antenna and a single reflector, according to various embodiments of the invention.

FIG. 5B shows an illustration of a top view of an oil shale deposit with a single antenna, an outer reflector, and an inner reflector, according to various embodiments of the invention.

FIG. 5C shows an illustration of a top view of an oil shale deposit with multiple antennae, an outer reflector, and an inner reflector, according to various embodiments of the invention.

FIG. 6 provides a flow diagram of a method for oil recovery, according to various embodiments of the invention.

FIG. 7 provides a flow diagram of a method for oil recovery from an existing reservoir site, according to various embodiments of the invention.

FIG. 8 shows a simplified illustration of an oil recovery system, modified for preprocessing of the recovered oil, according to various embodiments of the invention.

FIG. 9 shows a simplified illustration of a partial oil recovery system, modified with a generator 920 for preprocessing of the recovered oil, according to various embodiments of the invention.

FIG. 10 shows a simplified illustration of a partial oil recovery system, modified with a generator 920 and a perforated separator 1006 for preprocessing of the recovered oil, according to various embodiments of the invention.

FIG. 11 provides a flow diagram of a method for processing oil emulsions to separate oil and non-oil constituents of the emulsion, according to various embodiments of the invention.

FIG. 12 provides a flow diagram of a method for processing heavy oil into lighter oil, according to various embodiments of the invention.

DETAILED DESCRIPTION

This description provides example embodiments only, and is not intended to limit the scope, applicability, or configuration of the invention. Rather, the ensuing description of the embodiments will provide those skilled in the art with an enabling description for implementing embodiments of the invention. Various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention.

Thus, various embodiments may omit, substitute, or add various procedures or components, as appropriate. For instance, it should be appreciated that in alternative embodiments, the methods may be performed in an order different from that described, and that various steps may be added, omitted, or combined. Also, features described with respect to certain embodiments may be combined in various other embodiments. Different aspects and elements of the embodiments may be combined in a similar manner.

It should also be appreciated that the following systems, methods, and apparatuses may individually or collectively be components of a larger system, wherein other procedures may take precedence over or otherwise modify their application. Also, a number of steps may be required before, after, or concurrently with the following embodiments.

Embodiments of Oil Recovery Systems and Methods

Among other things, embodiments of the invention provide systems, devices, and methods for using high-power microwave radiation to heat oil shale deposits. Some embodiments use high-power klystrons to generate either continuous or pulsed microwave radiation. The microwaves may be applied to the oil shale deposits in situ, substantially at the depth of the oil shale deposit. In some geographic locations, oil shale deposits may be seen at relatively shallow depths (e.g., tens or hundreds of feet below the ground surface), while in other geographic locations, oil shale deposits may be significantly deeper (e.g., around 1000 feet below the ground surface).

Heating the oil shale may cause oil to be released (e.g., from kerogen). The oil released from the oil shale deposit may then be forced out to the ground surface by pressure from superheated steam generated from the heating of the oil shale and mineral deposits. For example, the heating of the oil shale deposit may generate approximately sixty to three hundred atmospheres of pressure. In some cases, this may provide sufficient pressure to force the released oil from the oil shale deposit to the ground surface without a need for additional sources of pressure (e.g., additional pumping of gases into the deposit).

In some embodiments, an oil recovery system is provided to help direct the released oil into a collector when it is forced to the ground surface. For example, the oil recovery system may include one or more pipes and other components sunk into a bore hole approximately to the depth of the oil shale deposit. The released oil may be forced into and up the bore hole via pipes and/or other components of the oil recovery system, and directed into a surface collector.

FIG. 1 shows a simplified system block diagram of an oil recovery system, according to various embodiments of the invention. The oil recovery system 100 includes a number of subsystems for heating an oil shale deposit to release oil and recovering the released oil in a useful way. In some embodiments, a power management system 104 provides power to a microwave generation system 108, which generates a certain type of high-power microwave radiation (e.g., pulse or continuous-wave). The radiation may be transmitted into an oil shale deposit 116 via an in-situ radiation system 112 (e.g., one or more antennae) for heating the oil shale deposit 116. As the oil shale deposit 116 heats, physical and/or chemical processes generate a set of released constituents 120 (e.g., oil, gases, etc.). The released constituents 120 may be handled by an oil extraction system 124 adapted at least to direct the released oil to an oil collection system 128. Oil collected in the oil collection system 128 may then be refined, transported, and/or otherwise processed by an oil processing system 132.

Embodiments of the oil recovery system 100 include a power management system 104 adapted to provide and manage power to the oil recovery system 100. Any useful power management system 104 may be used, including power generators, converters, etc. In some embodiments, the power management system 104 includes components to generate power on-site (e.g., near the oil shale deposit); while in other embodiments, the power management system 104 includes components to generate power off-site and transport the power on-site. In one embodiment, the power management system 104 includes components to couple with existing or supplemental utility provisions (e.g., the electrical grid, on-site wind turbines, etc.) and convert the power for use by the oil recovery system 100. In another embodiment, the power management system 104 includes components for recycling products of the oil recovery system 100 for use in generating power. For example, hot gases (e.g., fuel bearing gases) generated by the oil recovery system 100 may be recovered to generate electricity for the oil recovery system 100.

In some embodiments, the power management system 104 manages power provided for operation of a microwave generation system 108. The microwave generation system 108 may generate microwave radiation with certain characteristics (e.g., power, frequency, waveform, etc.), which may be transmitted to an oil shale deposit 116 via an in situ radiation system 112. In various embodiments, the microwave generation system 108 may include one or more klystrons, magnetrons, and/or other microwave generation components.

In certain embodiments, the microwave generation system 108 generates high-power microwave radiation. In one embodiment, a 1.5-4.5 megawatt, high-power klystron is used to generate approximately 2.856 GHz pulsed-wave microwave radiation at an efficiency of approximately forty-two percent (e.g., or 32 to 44 percent). In another embodiment, a one-hundred kilowatt (i.e., average power), high-power klystron is used to generate approximately 2.45 GHz continuous-wave microwave radiation at an efficiency of approximately sixty percent. It will be appreciated that high-power klystrons may be more efficient than low-power klystrons and may provide better penetration of the microwave radiation into the oil shale deposit. Further, continuous wave radiation may be generated more efficiently than pulse-wave radiation. However, pulse-wave radiation may provide higher peak electric field intensities for a given amount of energy expended, as compared to continuous-wave radiation.

In some embodiments, the release of oil from the oil shale deposit 116 may be related to the intensity of the microwave electrical field used to heat the oil shale. Because pulsed waves may tend to generate higher electrical field intensities than comparable continuous waves, it may be desirable in certain embodiments to use pulse-wave radiation. For a certain klystron, using pulse-wave radiation may substantially reduce its efficiency (e.g., from approximately sixty percent to approximately forty-four percent) and reduce the average power of the output (e.g., from approximately one hundred kilowatts to approximately twenty-two kilowatts for twenty-microsecond pulses). The advantages gained by an increase in field intensity, however, may offset or outweigh any disadvantages due to a decrease in output power or efficiency, as a net gain in output efficiency may result. For example, higher power radiation may generate a higher intensity electric field, which may in turn increase the rate of reaction (e.g., or reaction kinetics). As such, use of pulse power may cause more oil to be recovered per unit time (e.g., as compared with continuous-wave power), such that the microwave generation system 108 may run for a shorter total duration.

As such, some embodiments of the microwave generation system 108 are adapted to generate pulse-wave radiation, while other embodiments of the microwave generation system 108 are adapted to generate continuous-wave radiation. It will be appreciated that other characteristics of the radiation may also affect its usefulness for various purposes, including oil extraction efficiency, power consumption efficiency, compatibility with available components, compatibility with certain materials, etc. For example, embodiments of the microwave generation system 108 may be adapted to generate radiation of different polarities, waveforms, frequencies, amplitudes, etc.

Embodiments of the microwave generation system 108 include an in-situ radiation system 112 for transmitting the radiation generated by the microwave generation system 108 into the oil shale deposit 116. In some embodiments, the in-situ radiation system 112 includes one or more antennae. In certain embodiments, the antenna or antennae are situated in a bore hole sunk into the oil shale deposit 116 (e.g., see FIG. 3). In other embodiments, some or all of the antenna or antennae are situated outside the bore hole within the oil shale deposit 116. For example, a set of antennae may be distributed throughout the oil shale deposit 116 to allow for more efficient irradiating of certain parts of the oil shale deposit 116 (e.g., see FIG. 5A).

In various embodiments, the antenna or antennae may be in various proximities to one or more components of the microwave generation system 108. In one embodiment, the microwave generation system 108 includes a single generator (e.g., a single klystron), coupled with a single antenna using a wave guide. The wave guide is adapted to efficiently transmit the radiation from the klystron to the antenna for transmission to the oil shale deposit 116 (e.g., with substantially no loss). In another embodiment, the microwave generation system 108 includes a single generator coupled with multiple antennae using multiple wave guides. In yet another embodiment, the microwave generation system 108 includes multiple generators, each coupled with one or more antennae via one or more wave guides. It will be appreciated that, where there are multiple generators, antennae, and/or wave guides, each may be the same or different as the others, depending on known antenna design factors and characteristics of the oil shale deposit 116 and the components of the oil recovery system 100.

It will be appreciated that many types of antennae and wave guides are possible, according to embodiments of the invention. For example, the components of the in-situ radiation system 112 may be adapted to optimize transmission of a particular frequency, polarity, etc. In some embodiments, the shape, size, configuration, and/or other characteristics of the in-situ radiation system 112 are designed to affect the radiation in a particular way. For example, the shape may be selected to shape the radiation waveforms (e.g., a rectangular waveguide for rectangular waves (TE/TM modes)), the material may be selected for transmitting certain frequencies (e.g., copper, etc.), the antenna may be sized, slotted, and/or capped to increase transmission of certain frequencies, etc.

Embodiments of the in-situ radiation system 112 may include other components for added functionality. For example, it may be desirable to shield the antenna from certain environmental externalities, such as hot oil and gases being released from the oil shale deposit 116. As such, some embodiments include a sheath or other type of shield for surrounding an antenna. In certain embodiments, the sheath is designed to allow propagation of radiation, while shielding the antenna from the environmental externalities. For example, in one embodiment, the sheath has a ten-inch inner diameter and a wall thickness of 0.25 inches, and is manufactured from a composition of fused silica that is approximately one hundred percent transparent to the propagation of 2.45 GHz microwave radiation. In another embodiment, the sheath is manufactured from polytetrafluoroethylene (“PTFE”), high-density polyethylene (e.g., ECCO STOCK CPE from Emerson and Cummings), or fused silica (e.g., for added durability). In other embodiments, other components, like repeaters, optics, etc., are provided to aid in the transmission of desired radiation into the oil shale deposit 116. For example, certain radiation reflectors may be situated in the oil shale deposit 116 to reflect and/or focus unabsorbed radiation back into the oil shale deposit 116 or into a certain portion of the oil shale deposit 116.

Oil shale may typically manifest as a layered, deposited bed of kerogen (a bituminous solid) in a porous rock matrix. The rock matrix may contain associated free water and bound water, some of the water being water of crystallization in minerals, including carbonates, silicates, and phosphates mixed with pyrite. The intertwined matrices may contain geologically trapped water of around 1.5 to 3 percent by weight in the oil shale deposit 116, in addition to the water of crystallization in mineral constituents.

When high-power microwave radiation is propagated into the oil shale deposit 116, the radiation may be absorbed, though typically weakly, by the oil shale (which may have a low dielectric loss of around 0.4). Super-heated steam may be generated by vaporizing the geologically trapped water. The steam pressure may cause oil shale layers to fracture as the radiation penetrates into the oil shale deposit 116. Oil may begin to be released from the oil shale when the localized temperature reaches a particular level (e.g., around 450° C. at approximately fifty atmospheres or more). As the temperature continues to rise, more oil may be released. Additionally, at higher temperatures (e.g., 525° C.), there may be further cracking and some gasification of residual oil (e.g., promoted by catalysis from the minerals present).

As such, irradiating, and thereby heating, the oil shale deposit 116 may cause constituents 120 of the oil shale deposit 116 to be released. These released constituents 120 may include oil, as well as solid particulates, gases (e.g., steam, CO₂, etc.), and other constituents. In some cases, the released constituents 120 are simply released from the oil shale deposit 116 (e.g., trapped kerogen may be released). In other cases, the released constituents 120 include chemically generated and/or altered constituents (e.g., trapped water may be released as steam and some residual oil may be gasified).

Embodiments of the oil recovery system 100 include an oil extraction system 124 for handling the released constituents 120. In some embodiments, the oil extraction system 124 includes components for directing the flow of at least a portion of the released constituents 120. For example, the oil extraction system 124 may include pipes, conduits, drains, sieves, valves, pumps, etc. In certain embodiments, an area around the bore hole is treated to create high ground surface pressure. For example, compressed concrete and soil may be provided in the vicinity of the bore hole. In this way, pressure built up from the release of the released constituents 120 (e.g., pressure from superheated steam and other gases) may cause the released oil to find lower pressure exit paths, which may force at least a portion (e.g., substantially all) of the released oil into and up the bore hole (e.g., through one or more pipes). Certain seals, valves, and/or openings may be provided to control various pressures, to better direct the flow of oil.

In some embodiments, the oil extraction system 124 is adapted to direct the oil into an oil collection system 128. For example, the oil collection system 128 may include a surface oil collector for collecting any oil leaving the bore hole. Those of skill in the art will appreciate that many oil collection systems and techniques may be used in accordance with embodiments. For example, the oil collection system 128 may include components for storage, absorption, separation, skimming, etc.

For example, as gases are generated and/or released by the heating of the oil shale deposit 116, pressure in the region of the oil shale deposit 116 may increase. Appropriate management of this pressure may cause fracture of the oil shale deposit 116, which may cause the released constituents of the oil shale deposit 116, including released oil, to be forced (e.g., upwards) to lower pressure areas. By providing a low pressure environment within the bore hole (e.g., using piping), oil and other released constituents may be forced up the bore hole and into a surface collector.

Once the oil has been collected (e.g., or while the oil is being collected) by the oil collection system 128, embodiments may process the oil using an oil processing system 132. Some embodiments of the oil processing system 132 include components for refining the collected oil. It will be appreciated that the collected oil may be an oil emulsion. For example, the oil may contain various contaminants and/or impurities, the oil may be heavy (e.g., containing highly viscous macromolecules of hydrocarbons), etc. In these and other cases, the oil processing system 132 may be used to partially or completely refine the oil (e.g., into light crude oil, or some other form of useful oil). Other embodiments of the oil processing system 132 may include components for transporting the oil (e.g., pipelines, barges, tankers, drums, pumps, reservoirs, etc.).

FIG. 2 shows a simplified illustration of an oil recovery system, according to various embodiments of the invention. The oil recovery system 200 is situated in substantial proximity to a bore hole 202 which has been drilled into an oil shale deposit 206. The bore hole 202 may be drilled in any useful way, and may follow any useful path. In some embodiments, the bore hole 202 is drilled vertically, following a substantially straight path into the oil shale deposit. In other embodiments, the bore hole 202 is drilled horizontally or at an angle and/or following a non-linear path. It will be appreciated that the various components of embodiments of the invention may be oriented and/or situated to account for the direction of the bore hole 202 path (e.g., so as to ultimately direct released oil into a vertical section of the oil recovery system 200). In one embodiment, the bore hole 202 is approximately one thousand feet deep and approximately sixteen inches in diameter.

In some embodiments, at the surface of the bore hole 202 and extending outward for some distance, there may be layers of compacted soil and concrete 204. These layers of compacted soil and concrete 204 may help mitigate seepage of liquids and gases (e.g., oil, steam, etc.) through the ground surface in proximity to the bore hole 202. It will be appreciated that the layers of compacted soil and concrete 204 may be supplemented or supplanted by other materials to help minimize seepage through the surrounding ground surface. It will be further appreciated that, as discussed above, the layers of compacted soil and concrete 204 may cause underground pressure to develop to help direct the flow of released oil into oil extraction and collection components.

In some embodiments, a power supply 210 is provided. The power supply 210 may be part of a power management system, like the power management system 104 of FIG. 1. In some embodiments, all or part of the power supply 210 is situated outside the bore hole 202 on or near the ground surface (e.g., on the layers of compacted soil and concrete 204). In some embodiments, some or all of the power supply 210 is situated in close proximity to the bore hole 202 to minimize the distance between the power supply 210 and components requiring power (e.g., the generator 220).

Embodiments of the power supply 210 may include any system or group of systems capable of generating or supplying adequate power for the oil recovery system 200. In certain embodiments, the power supply 210 may include components (e.g., a transformer) capable of interfacing with an existing power grid. In other embodiments, the power supply 210 may include power generating components, like wind turbines, battery-coupled solar cells, nuclear reactors, hydroelectric generators, or any other useful power generator. The power supply 210 may also include back-up systems, fail safes, rectifiers, and other components to help maintain substantially constant power with certain characteristics (e.g., certain voltage, frequency, and lack of interference).

In some embodiments, the power supply 210 outputs power through one or more power cables 212. As such, one end of the power cable 212 may be coupled with the power supply 210. In some embodiments, all or a portion of the power cable 212 may be shielded (e.g., by additional tubing, conduit, or other shielding) to protect the cable from externalities that may damage the power cable 212 or affect the transmission of power or other signals through the power cable 212. By way of example, these externalities may include heat, moisture, or electromagnetic fields. In certain embodiments, the power cable(s) 212 may be manufactured or adapted to provide added functionality. For example, the power cable 212 may be split into multiple cables that can be coupled using integrated connectors. This may allow parts of the oil recovery system 200 to be more easily installed in pieces (e.g., subassemblies). In other examples, added functionality may be provided by supplying redundant power cables; including data cables or data transmission capabilities; insulating and/or shielding cables for handling electromagnetic interference, chaffing, exposure to environmental externalities, etc.; or in many other ways.

In some embodiments, the power cable 212 may be coupled with a generator 220, allowing the provision of power from the power supply 210 to the generator 220. Embodiments of the generator 220 may be included in a microwave generation system like the microwave generation system 108 of FIG. 1. In some embodiments, the generator 220 may be sunk into the bore hole 202 and situated in proximity to the depth where oil will be extracted from the oil shale deposit 206. In other embodiments, the generator 220 may be located at or near the ground surface. However, it will be appreciated that situating the generator 220 in proximity to the oil shale deposit 206 may increase the efficiency of the production of oil from the oil shale deposit 206.

Embodiments of the generator 220 are adapted to generate high-power microwave radiation. In some embodiments, a high-power klystron is used for generating approximately 2.45 GHz radiation at approximately one-half megawatt (e.g., or 100 kilowatts) of power. Certain embodiments of the generator 220 provide continuous-wave radiation, while other embodiments provide pulse-wave radiation. The generator 220 may be adapted to operate only at around one frequency or it may be adjustable (e.g., tunable). Further, the generator 220 may be adapted to generate particular polarizations, shapes, amplitudes, and other characteristics of radiation.

It will be appreciated that different types of radiation may be desirable depending on certain characteristics of the oil shale deposit 206. For example, high-power, 2.45-2.5 GHz radiation (e.g., at approximately 4.5 megawatt of power) may be desirable for oil shale deposits 206 of a certain type found at around one thousand feet below ground level. However, for shallower oil shale deposits 206 (e.g., tar sands, shallow pits, etc.), lower powers or different frequencies may be more desirable.

In some embodiments, the microwave radiation is propagated into the oil shale deposit 206 from the generator 220 via an antenna 224. The antenna 224 may be adapted to optimize the amount and direction of microwave radiation into the oil shale deposit 206. In some embodiments, the antenna 224 may be capped at the bottom to increase its effectiveness. It will be appreciated that many types and configurations of antenna 224 are possible, according to embodiments of the invention. An illustrative embodiment of the antenna 224 can be seen in FIG. 3.

FIGS. 3A and 3B show illustrations of a front view and a side view of an antenna, respectively, according to embodiments of the invention. For clarity, FIGS. 3A and 3B will be discussed in parallel. It will be appreciated that the illustrated antenna 300 is only one of many possible antennae, and should not be construed as limiting the invention in any way. For example, the specifics of the antenna 300 design may be adjusted for transmission of different frequencies, wave shapes, polarizations, directionality, etc.

In some embodiments, the antenna 300 may have a housing 330 with a length 302 of approximately one meter and a rectangular cross-section. The housing 330 may be manufactured separately or as part of a wave guide. In one embodiment, the antenna 300 is a linear portion of a WR 340 copper wave guide. The antenna 300 may be designed to transmit microwave radiation at 2.45 GHz.

In some embodiments, the housing 330 has two wide faces 306 opposite each other, each having an inner width 304-1 of approximately 3.40 inches, and two narrow faces 308, each having an inner width 304-2 of approximately 1.70 inches. The housing 330 may also be shorted at the bottom by an adjustable plug 332, and may be fused at the top to a flange 334 (e.g., attached to the wave guide). The housing 330 may further include a plurality of slots 310 which pierce the housing 330 and may be adapted to directionally propagate microwave radiation into an oil shale deposit 206 of FIG. 2. In some embodiments, the housing 330 and slots 310 are configured to generate substantially omni-directional radiation (e.g., by providing substantially 180-degree radiation from each of the wide faces 306).

In one embodiment, the housing 330 includes eight slots 310 on each of its two wide faces 306 and no slots 310 on its narrow faces 308. Each of the slots 310 may have a slot length 312 of 2.407 inches and a slot width 314 of 0.245 inches. The housing 330 may also provide a headspace 320 between the top of the antenna 300 and the top of the uppermost slot 310-1 of approximately 3.667 inches, a vertical spacing 322 of approximately 3.667 inches, and a bottom offset 324 between the bottom of the antenna 300 and the bottom of the lowest slot 310-8 of approximately 3.667 inches. Further, the slots 310 may each have a horizontal offset 326 from the centerline 328 of the antenna 300 of approximately 0.197 inches. It will be appreciated that many shapes, sizes, quantities, and positions of slots are possible for providing similar or different results.

Returning to FIG. 2, in some embodiments, microwave radiation output from the generator 220 propagates through a wave guide 222 before reaching the antenna 224. In certain embodiments, a flange 226 may be provided at an end of the wave guide 222 with which the antenna 224 may be coupled to the flange 226. In one embodiment, the antenna 224 may be engraved on the end of the wave guide 222 past the flange.

The wave guide 222 may be any useful shape to aid in the propagation of the microwave radiation. For example, the wave guide 222 may include a curve of approximately ninety degrees. This may be desirable where the output of the generator 220 propagates the microwave radiation in a direction substantially orthogonal to the orientation of the antenna 224. In one embodiment, the wave guide 222 is a WR 340-type copper wave guide with high surface finishes. However, it will be appreciated that the wave guide 222 may be manufactured from any effective material (e.g., copper).

In certain embodiments, other components may be added to assist the propagation of the microwave radiation into the oil shale deposit 206. For example, additional antennae may be provided in one or more locations throughout the oil shale deposit 206. Further, it may be desirable to monitor certain characteristics of the oil recovery system 200, and adjust the radiation accordingly.

In some embodiments, various monitor probes (e.g., dielectric probes) may be placed within the oil shale deposit 206 for monitoring the amount and/or characteristics of microwave radiation reaching certain parts of the oil shale deposit 206. For example, monitoring devices may be used at the ground surface to monitor the progress of oil release from the oil shale deposit 206 and the associated gasification and/or cracking of the oil shale deposit 206 (e.g., or other constituents associated with the kerogen in the oil shale). In one embodiment, dielectric probes are provided to identify different constituents of a deposit by exploiting differences in dielectric constants (e.g., water may have a dielectric constant of approximately 80, wet sand may have a dielectric constant of approximately 10-30, and shale may have a dielectric constant of approximately 5-15).

In another embodiment, a compact, portable, millimeter-wave spectrometer may be used at the ground surface to quantitatively monitor and detect the composition of the released oil emulsion. This quantitative monitoring may include the various proportions of the constituents in a gaseous volatile stream as they exit the oil transport pipe 230. Similarly, the various proportions of the constituents in a gaseous volatile stream may be monitored after being otherwise processed (e.g., by the oil processing system 132 of FIG. 1). For example, the volatiles may be captured in a quartz cell at very low pressures for millimeter-wave double-resonance spectroscopy to provide on-line dynamic data relating to the quantitative monitoring of the volatile stream.

In still other embodiments, millimeter-wave radiation is used for remote sensing. For example, sensors at the ground surface may be adapted to locate potentially rich deposits of oil shale rocks underground for exploration. This may help predict the potential of oil before installing an oil recovery system 200. Millimeter-wave radiation of known spectral distribution may be sent through a transmission line to suspected sites and the reflected radiation may be compared with the incident radiation. The comparison may tell if the deposit is rich in oil shale. This may provide a cost effective and reliable methodology to be used in oil exploration, including for finding oil deposits in oil shale underground.

In still other embodiments, the input and/or output of the generator 220 may be monitored to determine generator efficiency, power usage, output characteristics, etc. In any or all of the various embodiments that include monitoring, monitored information may be fed back to components or systems of the oil recovery system 200. In some embodiments, the information may be used to directly or indirectly adjust characteristics of the radiation supplied to the oil shale deposit 206. For example, components of the oil recovery system 200 may be adjusted to change the frequency, power, intensity, and/or other characteristics of the radiation.

In some embodiments, the antenna 224 may be enclosed within a sheath 228. The sheath 228 may be adapted to shield the antenna 224 from externalities, like superheated steam, CO₂, H₂, oil, and rock. Shielding the antenna 224 may require manufacturing the sheath 228 from certain materials and to certain specifications. For example, in one embodiment, the sheath 228 is cylindrical with a ten-inch inner diameter and a wall thickness of 0.25 inches.

In certain embodiments, the sheath 228 is adapted to be substantially transparent to a predetermined frequency of microwave radiation. For example, certain types of silica (e.g., fused silica) may be approximately one hundred percent transparent to the propagation of 2.45 GHz microwave radiation. In some embodiments, portions of the sheath 228 may include an opening which allows the passage of the wave guide 222, pipes, cables, and/or other components into or out from the sheath 228. These openings may be adapted to maintain the overall seal around the antenna 224 by using mechanical or chemical sealing components (e.g., sealing rings, grommets, etc.).

In some embodiments, the sheath 228 is sunk into the bore hole 202 and situated in proximity to the depth where oil will be extracted from the oil shale deposit 206. In certain embodiments, the generator 220 may be coupled with the outside of the sheath 228. The wave guide 222 may then be coupled between the generator 220 and the antenna 224 such that it passes through a sealed opening in the wall of the sheath 228. In this way, a sealed environment may be created for the propagation of the microwave radiation.

It will be appreciated that many types and configurations of sheath 228 are possible, according to embodiments of the invention. For example, the sheath 228 may be manufactured in any useful shape, size, material, thickness, etc. In some embodiments, the sheath 228 surrounds the generator 220 and/or other components of the oil recovery system 200. In embodiments that include multiple antennae 224, multiple sheaths 228 may be used to surround some or all of the antennae, individually or in groups.

In some embodiments, an oil transport pipe 230 is sunk into the bore hole 202. Oil released from the oil shale deposit 206 may be forced upward through the oil transport pipe 230 and into a surface oil collector 208. In one embodiment, the oil transport pipe 230 may have an approximately ten-inch inner diameter, may be manufactured from corrosion-resistant steel (e.g., 316 L steel), and may have a wall thickness of approximately 0.25 inches. It will be appreciated that the oil transport pipe 230 may be manufactured in any useful size and of any material capable of handling the pressure and heat required to force the released oil into the surface oil collector 208. Further, it will be appreciated that the oil transport pipe 230 may include multiple pipes, insulators, connectors, and/or other components for added effectiveness, ease of manufacture, ease of assembly and transport, etc.

In some embodiments, the surface oil collector 208 is situated at the surface opening of the bore hole 202. The surface oil collector 208 may be any of the types of surface oil collectors known in the art capable of collecting oil from the oil recovery system 200. In certain embodiments, the surface oil collector 208 may also help seal the top of the oil transport pipe 230 and the surrounding bore hole 202. This seal may help isolate the bore hole 202 environment, including the oil transport pipe 230, from externalities and may help maintain pressure within the bore hole 202 and the oil transport pipe 230.

In some embodiments, an outer pipe seal-off 236 may be provided to seal the bottom of the oil transport pipe 230. In one embodiment, the outer pipe seal-off 236 includes openings (e.g., ¼-inch diameter holes) to allow the flow of released oil emulsion into a region of the bore hole 202 above the outer pipe seal-off 236. In this way, the oil emulsion may be permitted to flow into the oil transport pipe 230. Further, the outer pipe seal-off 236 may provide cover and support to the generator 220.

In some embodiments, the outer pipe seal-off 236 is larger in diameter than the oil transport pipe 230. The outer pipe seal-off 236 may be coupled to the bottom of the oil transport pipe 230 in any manner known to the art to be effective for sealing the bottom of the outer pipe seal-off 236. The outer pipe seal-off 236 may further be coupled to the top of the sheath 228, helping to seal the top of the sheath 228 and to couple the sheath 228 with the oil transport pipe 230. In some embodiments, the outer pipe seal-off 236 may include one or more openings to allow passage of components (e.g., cables, pipes, etc.) through the outer pipe seal-off 236 from the oil transport pipe 230 to the sheath 228. It will be appreciated that the openings in the outer pipe seal-off 236 may be sealed in any effective way to maintain the bottom seal of the oil transport pipe 230 and the top seal of the sheath 228.

In certain embodiments, a conduit 232 may be provided. The conduit 232 may be situated within the oil transport pipe 230 and may be similarly sealed (e.g., by the surface oil collector 208 at the top and by the outer pipe seal-off 236 at the bottom). In one embodiment, the conduit 232 may provide a sealed region within the oil transport pipe 230 as a conduit for the power cable 212. In this embodiment, the conduit 232 may have a five-inch inner diameter and a wall thickness of 0.25 inches. Further, in this embodiment, the power cable 212 may pass through the oil transport pipe 230 via the conduit 232, thereby being shielded from the environment in the remaining portion of the oil transport pipe 230.

It will now be appreciated that the power cable 212 may run from the power supply 210 to the generator 220 through a sealed environment. More specifically, in one embodiment, the power cable 212 may run from the power supply 210, through the surface oil collector 208, into the sealed conduit 232, through a sealed opening in the outer pipe seal-off 236, into the sheath 228, through a sealed opening in the sheath 228, and into the generator 220.

Various embodiments may provide improved shielding and/or an improved seal, particularly for the routing of the power cable 212 from the power supply 210 to the generator 220. In one embodiment, the generator 220 may be coupled in a sealed way to the side of the sheath 228 (e.g., still providing space for air cooling of the generator). In another embodiment, a sealed conduit 232 may be provided to enclose the power cable 212 as it routes between the power supply 210 and the surface oil collector 208. In yet another embodiment, a sealed conduit 232 may be provided to enclose the power cable 212 as it routes between the outer pipe seal-off 236, through the sheath 228, and to the generator 220.

It will be appreciated that these sealed regions and conduits 232 may be used for routing and/or sealing components other than the power cable 212. In some embodiments, thermal management components are run through and/or incorporated with the conduit 232. For example, pipes, vents, fans, and/or other components may be used to maintain a desirable operating temperature for the generator. In another embodiment, signal cables are run through the conduit 232. For example, cables may be run through the conduit 232 to communicate control signals, feedback signals, emergency shutdown signals, remote monitoring signals, etc.

In some embodiments, a perforated region 234 (e.g., a perforated pipe, perforations in the oil transport pipe 230, etc.) is provided to allow oil to flow into the oil transport pipe 230. It will be appreciated that the perforated region 234 may be adapted to allow the flow of oil while still maintaining pressure within the oil transport pipe 230. In one embodiment, the perforated region 234 is a one-meter region in the lower portion of the oil transport pipe 230. The perforated region 234 may be situated in proximity to the depth where oil will be extracted from the oil shale deposit 206.

In certain embodiments, a flow ring seal 238 is provided. The flow ring seal 238 may be coupled with and may surround the outside of the oil transport pipe 230. Further, the flow ring seal 238 may be situated at a shallower depth than the perforated region 234 to help direct the flow of released oil into the oil transport pipe 230.

In various embodiments, the oil recovery system 200 may be assembled in different ways. In one embodiment, the bore hole 202 is drilled and the area surrounding the bore hole 202 (on the surface) is reinforced with the layers of compacted soil and concrete 204. All or a portion of the components of the oil recovery system 200 may then be lowered into the bore hole 202 with the exception of the power supply 210 and the surface oil collector 208.

In one embodiment, the generator 220, wave guide 222, antenna 224, power cable 212, and sheath 228 may be pre-coupled into a first subassembly. The oil transport pipe 230, conduit 232, perforated region 234, and flow ring seal 238 may be pre-coupled into a second subassembly. The power cable 212 may be passed from the first subassembly, through a sealed opening in the outer pipe seal-off 236, and through the conduit 232 in the second assembly. The two subassemblies may then be fused together at the outer pipe seal-off 236 to form a third subassembly. This third subassembly may then be lowered into the bore hole 202 to place all the components in the third subassembly in their appropriate locations. The power cable 212 may then be passed through the surface oil collector 208, and the surface oil collector 208 may be installed to seal the top of the oil transport pipe 230 and to seal the top of the bore hole 202. The power supply 210 may then be installed at the ground surface and the power cable 212 may be coupled to the power supply 210.

In other embodiments, assembly of the oil recovery system 200 may include lowering components into the bore hole 202 individually, in groups, or as subassemblies. For example, the generator 220, wave guide 222, antenna 224, and sheath 228 may then be sunk into the bore hole 202 before being coupled with other components of the oil recovery system 200. Further, the shape and size of the bore hole 202 may be related to or may dictate how the oil recovery system 200 is assembled.

In one embodiment, the bore hole 202 is approximately sixteen inches in diameter and one thousand feet deep. In this embodiment, the flow ring seal 238 and outer pipe seal-off 236 have approximately the same diameter as the bore hole 202 (i.e., sixteen inches), and the oil transport pipe 230 and sheath 228 have diameters of approximately ten inches. A subassembly with these dimensions, incorporating the components of the third subassembly described above, may fit tightly into the bore hole 202. It will be appreciated that components of various embodiments may be modified to fit bore holes 202 of different shapes, sizes, and depths.

Some embodiments, at least through the use of appropriately sized and oriented components, may provide a substantially sealed environment when installed. The substantially sealed environment may then allow the microwave radiation to propagate into the oil shale deposit 206, and may allow pressure from super-heated steam to force the released oil from the oil shale deposit 206 to flow upward through the oil transport pipe 230 and into the surface oil collector 208. Further, certain components of the oil recovery system 200 (e.g., the outer pipe seal-off 236, the conduit 232, and the sheath 228) substantially protect other components of the oil recovery system 200 (e.g., the generator 220, the antenna 224, and the power cable 212) from coming into contact with the high temperatures and pressures relating to the flow of released oil, steam, and gases.

It will be appreciated that other components may be added to the oil recovery system 200 to increase its effectiveness. In some embodiments, multiple antennae 224 are distributed throughout the oil shale deposit 206 to more directly irradiate certain portions of the oil shale deposit 206. Because field intensities may drop-off as a function of distance from the source, placing more sources (e.g., antennae) throughout the oil shale deposit 206 may increase the average field intensity across the oil shale deposit 206.

FIG. 4 shows an illustration of a top view of an oil shale deposit 410 with multiple distributed antennae 440, according to various embodiments of the invention. In some embodiments, a bore hole 420 is located in a location central to the oil shale deposit 410. In other embodiments, the bore hole 420 is located in some other location (e.g., for added convenience, for easier drilling, to avoid surface uses of the land, etc.). An oil transport pipe 430 and/or other oil recovery systems and components may be situated in or near the bore hole 420. In some embodiments, each antenna 440 is surrounded (e.g., and shielded) by a sheath 445.

Some embodiments of the oil recovery system (e.g., oil recovery system 200 of FIG. 2) include one or more radiation handling components situated in the oil shale deposit (e.g., oil shale deposit 206 of FIG. 2). The radiation handling components may be adapted to direct radiation in the oil shale deposit 410. For example, the radiation handling components may reflect, deflect, focus, polarize, or otherwise affect the direction or other characteristics of the radiation as it passes through the deposit.

In various embodiments, oil recovery systems like the one shown in FIG. 4 are used to recover oil from oil shale deposits 410 or reservoirs, where the oil is difficult to access. For example, the oil shale deposit 410 or reservoir may be at the site of a previously drilled well, a spent well, an old serviced and abandoned well, a difficult-to-access find, etc. In these embodiments, water (e.g., some a measured amount) may be pumped into the vicinity of the oil shale deposit 410. A number of microwave sources (e.g., klystrons, antennae, etc.) and/or accessories may be placed at appropriate depths and locations to generate microwaves adapted to be readily absorbed by the water. For example, klystrons may be provided, each klystron being adapted to generate approximately 2.45 GHz radiation at approximately 100 kilowatts of continuous-wave power.

The absorption of the radiation by the water may cause the water to heat and generate steam. The steam, along with the in situ microwave heating of the oil in the oil shale deposit, may cause the oil emulsion to be forced into an oil transport pipe 430. In various embodiments, the oil transport pipe 430 may be suitably oriented in an existing (e.g., previously drilled) well or the wells may be dug out in appropriate orientations and/or depths.

It will be appreciated that other additional components may improve the efficacy of the oil recovery system. For example, only a portion of the microwave radiation may be absorbed by the oil shale deposit 410, and the remainder may be essentially wasted. However, it may be possible to provide one or more reflectors to reflect the unabsorbed radiation back into the deposit. This may increase the amount of radiation absorbed by the deposit and decrease the amount of waste.

FIG. 5A shows an illustration of a top view of an oil shale deposit 510 with a single antenna 540 and a single reflector 550, according to various embodiments of the invention. An oil transport pipe 530 is situated in a bore hole 520 located in the oil shale deposit 510. The reflector 550 is situated outside the bore hole 520. In some embodiments, the reflector 550 surrounds the bore hole 520 at some distance. It will be appreciated that the reflector 550 may be any useful shape and any useful distance from the bore hole 520.

As radiation leaves the antenna 540, some is absorbed by the oil shale deposit 510 (e.g., causing it to heat), while other radiation is not absorbed. In fact, a low dielectric loss in some oil shale deposits 510 may result in a low percentage of the radiation being absorbed. However, when the unabsorbed radiation reaches the reflector 550, it may be reflected back into the oil shale deposit 510 for increased absorption. The reflector 550 may be manufactured from any suitable material for reflecting the radiation. In one embodiment, the reflector 550 is an aluminum cylinder. In certain embodiments, the reflector 550 is further treated (e.g., coated) to be better compatible with the environment of the oil shale deposit 510 (e.g., to avoid corrosion).

FIG. 5B shows an illustration of a top view of an oil shale deposit 510 with a single antenna 540, an outer reflector 550, and an inner reflector 560, according to various embodiments of the invention. An oil transport pipe 530 is situated in a bore hole 520 located in the oil shale deposit 510. The outer reflector 550 is situated outside the bore hole 520. In some embodiments, the outer reflector 550 surrounds the bore hole 520 at some distance. The inner reflector 560 may also be situated outside the bore hole 520, but in closer proximity to the bore hole 520 than the outer reflector 550. In some embodiments, the inner reflector 560 surrounds the bore hole 520 at a relatively close distance. The inner reflector 560 is manufactured to be substantially transparent to certain microwave radiation in one direction, while being substantially reflective to the microwave radiation in the other direction. For example, the inner reflector 560 may include multiple layers (e.g., which may be separated) to provide this functionality.

As radiation leaves the antenna 540, it passes through the inner reflector 560 in the direction in which the inner reflector 560 is substantially transparent to the radiation. As the radiation passes into the oil shale deposit 510, some is absorbed by the oil shale deposit 510, while other radiation is not absorbed. When the unabsorbed radiation reaches the outer reflector 550, it may be reflected back into the oil shale deposit 510 for increased absorption. On the second pass, additional radiation may be absorbed by the oil shale deposit 510 and some radiation may still remain unabsorbed. The remaining unabsorbed radiation may come back in contact with the outside of the inner reflector 560 (e.g., the direction in which the inner reflector 560 is substantially reflective to the radiation). The remaining unabsorbed radiation may be once again reflected back into the oil shale deposit 5 10. In this way, the radiation may essentially remain trapped in the oil shale deposit 510, potentially increasing the efficiency of absorption by the oil shale deposit 510.

FIG. 5C shows an illustration of a top view of an oil shale deposit 510 with multiple antennae 540, an outer reflector 550, and an inner reflector 560, according to various embodiments of the invention. An oil transport pipe 530 is situated in a bore hole 520 located in the oil shale deposit 510. The outer reflector 550 is situated outside the bore hole 520. In some embodiments, the outer reflector 550 surrounds the bore hole 520 at some distance. The inner reflector 560 may also be situated outside the bore hole 520, but in closer proximity to the bore hole 520 than the outer reflector 550. In some embodiments, the inner reflector 560 surrounds the bore hole 520 at a relatively close distance. As illustrated, the antennae 540 may all be located outside the bore hole 520.

In some embodiments, the antennae 540 are located outside the bore hole 520, between the inner reflector 560 and the outer reflector 550. Because all the antennae 540 may be situated on one side of the inner reflector 560, the inner reflector 560 may be manufactured to be substantially reflective to certain microwave radiation from either one or both directions. In this way, radiation from any or all of the antennae 540 may reflect between the inner reflector 560 and the outer reflector 550 to be more efficiently absorbed by the oil shale deposit 510.

FIG. 6 provides a flow diagram of a method for oil recovery, according to various embodiments of the invention. The method 600 begins at block 610 by generating microwave radiation. For example, the microwave radiation may be generated by a klystron or other microwave generator. As discussed above, in some embodiments, the radiation is generated at block 610 in situ. For example, the radiation may be generated from a depth of approximately one thousand feet, rather than attempting to propagate the microwave radiation from the surface through one thousand feet of depth (e.g., via a wave guide).

The microwave radiation generated at block 610 may then be transmitted at block 620 into an oil shale deposit. In some embodiments, the microwave radiation is transmitted at block 620 by an antenna, adapted to transmit radiation at a particular microwave frequency. The antenna may be further adapted to transmit radiation at a certain amplitude, polarity, etc. In some embodiments, the generation at block 610 and/or the transmission at block 620 may be tunable based on one or more conditions relating to the oil recovery.

When the radiation propagates into the oil shale deposit at block 620, the oil shale may be heated. Environmental changes may result from the heating. For example, water trapped within the deposit may become super-heated steam. The pressure of the steam may cause cracking and other events within the oil shale. For this and other reasons, oil and other gases may be released from the oil shale. Pressure from released gases may also cause the oil and other released constituents to be forced from the oil shale deposit into a lower pressure environment.

At block 630, the released oil may be extracted and/or collected. Extracting the oil at block 630 may include providing a lower pressure environment (e.g., piping in a bore hole) into which the oil and other released constituents may flow. The oil may then be pumped or otherwise forced to the surface for collection. In some embodiments, pressure from the super-heated steam may force the released oil up to the surface for collection.

It will be appreciated that the released oil may not be pure or refined. Rather, the released oil may contain impurities, or it may be mixed with other liquids, solids, or gases. For this and other reasons, it may be desirable to refine and/or process the oil at block 640. Refining the oil at block 640 may remove or separate impurities (e.g., water, CO₂, CH₄, C₂H₆, oxides of sulfur, etc.), or perform any other function useful for improving the usefulness of the released oil for some purpose. For example, processing the oil may include transporting the oil or other constituents to another location, or recycling a portion of the released constituents to provide power for steps of the oil recovery method 600.

In some embodiments, certain information may be monitored at block 650 and fed back to steps of the method 600 for use in adapting the method to changing conditions. For example, it may be desirable to adapt characteristics of the generated radiation, how or where the radiation is transmitted into the oil shale deposit, how released constituents are processed, etc.

FIG. 7 provides a flow diagram of a method for oil recovery from an existing reservoir site, according to various embodiments of the invention. The method 700 begins at block 710 by providing an oil collection system. At block 720, water is pumped into an underground oil reservoir site. Microwave radiation is generated at block 730 at a power and/or frequency adapted for converting the pumped water into steam.

At block 740, the microwave radiation is transmitted into the reservoir site using multiple in situ radiation sources. The radiation may be absorbed by the water, causing the water to convert to steam. The same or other radiation (e.g., radiofrequency) may be used to heat the oil in the oil reservoir site. Pressure from the steam may cause the oil to be forced into the oil collection system.

Embodiments of Oil Refinement Systems and Methods

In various embodiments of the invention, heating an oil shale deposit may cause an oil emulsion to be released. For example, volatile products (e.g., water, steam, hydrogen, methane, etc.) may be formed underground and may become mixed with the released oil. In fact, any type of oil extraction from an underground oil source (e.g., oil shale or a reservoir) may produce an oil emulsion containing both oil and other constituents. Additionally, the released oil may, in some cases, contain large macromolecules, which may cause the released oil to be heavy, viscous, and difficult to transport to the ground surface. For at least these reasons, oil (or an oil emulsion) extracted from a site may require certain processing before it may be used in various applications. The processing may be used to refine the oil, including removing impurities and breaking down macromolecules.

It will be appreciated that it may be desirable to preprocess the emulsion while still underground. In this way, the extracted product may be better compatible with direct shipment to refineries or other uses. FIG. 8 shows a simplified illustration of an oil recovery system, modified for preprocessing of the recovered oil, according to various embodiments of the invention. The oil recovery system 800 may include all the same or similar components to those in the oil recovery system 200 of FIG. 2, including the oil transport pipe 230, the generator 220, the antenna 224, and the surface oil collector 208. Therefore, it will be appreciated that some or all of the additional components of the oil recovery system 800 may be additions or modifications to the oil recovery system 200 of FIG. 2.

In some embodiments, the generator 220 is adapted to provide a second radiation output, other than the radiation transmitted into the oil shale deposit 206. For example, the second radiation output may have the same or different radiation characteristics, including frequency, polarization, amplitude, etc. The characteristics of the second radiation output may be determined as a function of the type of refinement desired. For example, it may be desirable to set the radiation characteristics to gasify certain constituents of the released oil emulsion, to separate the oil from the non-oil constituents, to break down large macromolecules in the oil, etc. In one embodiment, the second radiation output is at the same frequency as the first radiation output (e.g., 2.45 GHz), but a significantly lower amplitude (e.g., two to five kilowatts of power).

It will be appreciated that many ways are possible for generating the two outputs from a single generator 220 or microwave generation system. For example, a single generation system may include multiple generators, which may or may not be collocated. In another example, a single generator may use various components (e.g., optics, filters, transformers, antennae, etc.) to change the characteristics of the radiation passing through one or both outputs. It will be further appreciated that similar or different techniques may be used to generate more than two radiation outputs.

In some embodiments, the second radiation output propagates through a wave guide 822. In one embodiment, the wave guide 822 is a WR 284-type wave guide. In some embodiments, the end of the wave guide 822 is coupled with a window 826. The window 826 may be adapted to be substantially transparent to the second radiation output coming from the generator 220. In one embodiment, the window 826 is manufactured from high-density polyethylene with substantial transparency to 2.45 GHz microwave radiation.

The window 826 may further be manufactured or installed such that the window 826 may handle the temperatures, pressures, and other environmental conditions which may at times be present within the oil transport pipe 230. For at least this reason, the coupling between the wave guide 822 and the window 826 may form a seal or may be enclosed within a sealing assembly 824. In one embodiment, the sealing assembly 824 may be a flange “O”-ring assembly.

In some embodiments, a shield 828 is provided between the window 826 and the contents of the oil transport pipe 230. Certain embodiments of the shield 828 are substantially opaque to the output radiation passing through the window 826, thereby preventing the radiation from reaching the contents of the oil transport pipe 230 when engaged. Other embodiments of the shield 828 are further adapted to protect the window 826 from certain conditions within the oil transport pipe 230. For example, when the oil level gets too close to the window 826, it may be desirable to engage (e.g., close) the shield 828 over the window 826 to protect the window 826 from being damaged by exposure to the contents of the oil transport pipe 230 (e.g., the heated oil and other constituents).

In some embodiments, the shield 828 is electrically controlled, such that it may be opened and closed (or otherwise moved out of the way) using electromechanical or similar control mechanisms. For example, the shield 828 may include a set of louvers placed in parallel with one another (like window blinds) which may be rotated by a motor. In certain embodiments, some or all of the control mechanisms for the shield 828 may be located remotely to the shield 828. In one embodiment, a switch may be located in proximity to the ground surface in operative communication with a motor located at the shield 828. The switch at the ground surface may be used to remotely open and close the shield 828. In this way, it may be possible to adjust the amount and timing of radiation which reaches the contents of the oil transport pipe 230 without directly controlling the output of the generator 220.

By allowing the second radiation output to flow into the oil transport pipe 230, the second radiation output may be absorbed by any oil emulsion that has collected within the oil transport pipe 230. When the second radiation output is absorbed, the oil emulsion may release water, hydrogen, steam, light hydrocarbons (e.g., methane and ethane), and other constituents of the emulsion. In this way, the oil may be refined and/or separated from other constituents of the oil emulsion. The processed (e.g., refined) oil may be forced up the oil transport pipe 230 separately from the other components released from the oil emulsion.

Embodiments of the oil recovery system 800 include an oil exit pipe 830 for allowing the oil to escape from the oil transport pipe 230. In certain embodiments, the oil may then be collected at the surface in a surface collector 208 in processed form. In some embodiments, a volatiles exit pipe 840 may be provided to allow the escape of some or all of the constituents of the oil emulsion other than the processed oil. In certain embodiments, the non-oil constituents may then be collected. For example, the non-oil constituents may be collected in a separate surface collection unit or in a separate area of the surface collector 208. In certain embodiments, either or both of the volatiles exit pipe 840 and the oil exit pipe 830 may include a plurality of pipes or other transport components.

It will be appreciated that the other components may be processed and/or transported for use in other applications. For example, the gaseous products may contain fuels that can be used to provide electricity. Additionally, energy generated from those other components (e.g., through conversion into fuel, by using the gas flow to generate power, etc.) may be recycled into the power supply 210 to improve the efficiency of the oil recovery system 800.

It will be appreciated that other types of oil refinements systems are possible according to embodiments of the invention. FIG. 9 shows a simplified illustration of a partial oil recovery system, modified with a generator 920 for preprocessing of the recovered oil, according to various embodiments of the invention. In some embodiments, the partial oil recovery system 900 includes components and/or functionality similar to the oil recovery system of FIG. 2. In other embodiments, the partial oil recovery system 900 includes any components and/or functionality useful for extracting an oil emulsion into an oil transport pipe 230.

In some embodiments, the generator 920 is adapted to provide multiple radiation outputs. In certain embodiments, the generator 920 may be provided in addition to a first generator (e.g., like the generator 220 of FIGS. 2 and 8). It will be appreciated that, in embodiments where there are multiple generators (e.g., generator 920 and generator 220 of FIG. 8), each generator may be powered by the same or different power supplies 210. In certain embodiments, a single power supply 210 (or power management system) provides multiple outputs to the multiple generators. In other embodiments, some or all of the generators are coupled with separate power supplies.

The radiation outputs may have the same or different radiation characteristics from one another, including frequency, polarization, amplitude, etc. The characteristics of the second radiation output may be determined as a function of the type of refinement desired. For example, it may be desirable to set the radiation characteristics to gasify certain constituents of the released oil emulsion, to separate the oil from the non-oil constituents, to break down large macromolecules in the oil, etc. In one embodiment, the second generator is a magnetron, adapted to generate approximately 2.45 GHz at approximately five kilowatts of power. In another embodiment, multiple generators 920 are provided, each being adapted to generate one or more radiation outputs.

In some embodiments, the radiation outputs propagate through wave guides 822 (e.g., WR 284-type wave guides). In certain embodiments, the ends of the wave guides 822 are coupled with windows 826. The windows 826 may be adapted to be substantially transparent to the radiation outputs coming from the generator 920. In one embodiment, the windows 826 are manufactured from high-density polyethylene with substantial transparency to 2.45 GHz microwave radiation.

The windows 826 may further be manufactured or installed such as to handle the temperatures, pressures, and other environmental conditions which may at times be present within the oil transport pipe 230. For at least this reason, the coupling between the wave guides 822 and the windows 826 may form a seal or may be enclosed within sealing assemblies 824. In one embodiment, the sealing assemblies 824 include flange “O”-ring assemblies.

In some embodiments, shields 828 are provided between the windows 826 and the contents of the oil transport pipe 230. Certain embodiments of the shields 828 are substantially opaque to the output radiation passing through the windows 826, thereby preventing the radiation from reaching the contents of the oil transport pipe 230 when engaged. Other embodiments of the shields 828 are further adapted to protect the windows 826 from certain conditions within the oil transport pipe 230.

For example, when the oil level in the oil transport pipe 230 is below the lower window, it may be desirable to engage (e.g., close) the upper shield 828-1, thereby effectively closing the upper window 826-1. This may cause microwave radiation to be transmitted only from the lower window 826-2. When the oil level rises too close to the level of the lower window 826-2, it may be desirable to engage the lower shield 828-2 over the lower window 826-2 to protect the lower window 826-2 from being damaged by exposure to the contents of the oil transport pipe 230 (e.g., the heated oil and other constituents). The upper shield 828-1 may then be disengaged from the upper window 826-1, thereby effectively re-opening the upper window 826-1 and causing microwave radiation to be transmitted only from the upper window 826-1.

In some embodiments, some or all of the shields 828 are electrically controlled, such that it may be opened and closed (or otherwise moved out of the way) using electromechanical or similar control mechanisms. In certain embodiments, some or all of the control mechanisms for the shields 828 may be located remotely to the shields 828. In this way, it may be possible to adjust the amount and timing of radiation which is transmitted to the contents of the oil transport pipe 230 from the various windows 826 without directly controlling the output of the generator 920.

As in the oil recovery system 800 of FIG. 8, allowing the radiation output or outputs to flow into the oil transport pipe 230 may cause the oil emulsion to release oil and non-oil constituents of the emulsion. In some embodiments, oil may exit through an oil exit pipe 830 and non-oil constituents may exit through a volatiles exit pipe 840. In certain embodiments, the oil and or non-oil constituents may then be collected in a surface collector 208.

FIG. 10 shows a simplified illustration of a partial oil recovery system, modified with a generator 920 and a perforated separator 1006 for preprocessing of the recovered oil, according to various embodiments of the invention. In some embodiments, the partial oil recovery system 1000 includes components and/or functionality similar to the oil recovery system of FIG. 2. In other embodiments, the partial oil recovery system 1000 includes any components and/or functionality useful for extracting an oil emulsion into an oil transport pipe 230.

In some embodiments, the generator 920 is adapted to generate a radiation output. In certain embodiments, the generator 920 is provided in addition to a first generator (e.g., like the generator 220 of FIGS. 2 and 8). The radiation outputs may have the same or different radiation characteristics from one another, including frequency, polarization, amplitude, etc. The characteristics of the second radiation output may be determined as a function of the type of refinement desired. For example, it may be desirable to set the radiation characteristics to gasify certain constituents of the released oil emulsion, to separate the oil from the non-oil constituents, to break down large macromolecules (e.g., by catalytic action) in the oil, etc. In one embodiment, the second generator is a magnetron, adapted to generate approximately 2.45 GHz at approximately five kilowatts of power.

It may be desirable, in some cases, to locate the generator 920 at the ground surface, or otherwise remotely to the oil transport pipe 230. In some embodiments, the radiation output propagates into the oil transport pipe 230 through a wave guide 822 (e.g., a WR 284-type wave guide). In certain embodiments, the end of the wave guide 822 is coupled with a window 826. The window 826 may be adapted to be substantially transparent to the radiation outputs coming from the generator 920. In one embodiment, the window 826 is manufactured from high-density polyethylene with substantial transparency to 2.45 GHz microwave radiation.

The window 826 may further be manufactured or installed such as to handle the temperatures, pressures, and other environmental conditions which may at times be present within the oil transport pipe 230. For at least this reason, the coupling between the wave guide 822 and the window 826 may form a seal or may be enclosed within a sealing assembly 824. In one embodiment, the sealing assembly 824 includes a flange “O”-ring assembly.

In some embodiments, a shield 828 is provided between the window 826 and the contents of the oil transport pipe 230. Certain embodiments of the shield 828 are substantially opaque to the output radiation passing through the window 826, thereby preventing the radiation from reaching the contents of the oil transport pipe 230 when engaged. Other embodiments of the shield 828 are further adapted to protect the window 826 from certain conditions within the oil transport pipe 230.

In some embodiments, the oil transport pipe 230 includes a perforated separator 1006. The perforated separator 1006 may provide one or more functions, including dividing the oil transport pipe 230 into an upper region 1002 and a lower region 1004. An oil emulsion may enter the lower region 1004 of the oil transport pipe 230 (e.g., through the perforated region 234 of FIG. 2). Pressure from super-heated steam or some other source may then force the oil emulsion upward through the oil transport pipe 230 from the lower region 1004 to the upper region 1002 for surface collection by a surface collector 208. It is worth noting that, where the oil transport pipe includes a perforated region (e.g., the perforated region 234 of FIG. 2), perforations in the perforated separator 1006 may be similar to or different from perforations in the perforated region of the oil transport pipe 230.

It will be appreciated that, while the perforations in the perforated separator 1006 may be sized large enough to permit the flow of oil and/or other constituents from the lower region 1004 to the upper region 1002, the perforations may be sized small enough to substantially prevent microwave radiation propagated into the lower region 1004 from leaking into the upper region 1002. For example, in one embodiment, the perforated separator is manufactured with perforations having approximately ⅛-inch diameters. This size of perforation may be substantially opaque to 2.45 GHz radiation. As such, the perforations may cause radiation coming through the window 826 to be substantially trapped in the lower region 1004, while still allowing the flow of oil into the upper region 1002.

In certain embodiments, wave guide 822, the window 826, the shield 828, and/or the sealing assembly 824 are installed within an opening in the perforated separator 1006. This may allow propagation of radiation from the generator 920 into the lower region 1004 of the oil transport pipe 230 through the wave guide 822 and the window 826 (i.e., without being blocked by the perforated separator 1006). Using the sealing assembly 824 in this way may, for example, create a seal at the opening in the perforated separator 1006, or may shield the wave guide 822 and/or window 826 from direct contact with the perforated separator 1006.

In one embodiment, the distance 1050 from the ground surface 204 to the window 826 (and the perforated separator 1006) is approximately 100 feet. As microwave radiation propagates through the wave guide 822, there may be significant attenuation. As such, situating the window 822 and the perforated separator 1006 relatively close to the ground surface level 204 may allow propagation of radiation into the lower region 204 without significant attenuation.

As in the oil recovery system 800 of FIG. 8 and the partial oil recovery system 900 of FIG. 9, allowing the radiation output or outputs to flow into the oil transport pipe 230 may cause the oil emulsion to release oil and non-oil constituents of the emulsion. In some embodiments, oil may exit through an oil exit pipe 830 and non-oil constituents may exit through a volatiles exit pipe 840. In certain embodiments, the oil and or non-oil constituents may then be collected in a surface collector 208.

FIG. 11 provides a flow diagram of a method for processing oil emulsions to separate oil and non-oil constituents of the emulsion, according to various embodiments of the invention. The method 1100 begins at block 1110 by receiving an oil emulsion at an oil extraction system (e.g., in an oil transport pipe). The oil emulsion may be received in any effective way. In some embodiments, the oil emulsion is received by a process similar to that of method 600 of FIG. 6 (e.g., by performing steps 610, 620, and 630).

At block 1120, microwave radiation is generated, the microwave radiation being of a type adapted to refine an oil emulsion. For example, the microwave radiation may be five-to-100 kilowatt microwave (e.g., 2.45 GHz) radiation. The microwave radiation may be transmitted into the oil emulsion at block 1130 to process the oil emulsion. For example, heating the oil emulsion with the radiation may cause oil and non-oil constituents of the emulsion to separate. The oil may be collected at block 1140 by a first collection system, and the non-oil constituents may be collected at block 1150 by a second collection system. In some embodiments, the first and second collection systems may be separate regions of one collection system.

In some embodiments, the composition of the oil emulsion may be analyzed at block 1160. For example, the composition of the oil emulsion may be analyzed before and/or after processing. Information from the analysis may, in certain embodiments, be fed back to other steps of the method 1100 to adjust, tune, or otherwise affect performance of the step of the method 1100. For example, the information may be fed back to block 1120 or block 1130 to affect the generation and/or transmission of radiation, respectively.

FIG. 12 provides a flow diagram of a method for processing heavy oil into lighter oil, according to various embodiments of the invention. The method 1200 begins at block 1210 by receiving heavy oil at an oil extraction system (e.g., in an oil transport pipe). The heavy oil may be received in any effective way. For example, large reservoirs of heavy oil may exist in multiple locations around the world.

At block 1220, microwave radiation is generated, the microwave radiation being of a type (e.g., continuous-wave or pulse) adapted to refine heavy oil. For example, large macromolecules (e.g., of hydrocarbons) may cause heavy oil to be highly viscous and difficult to transport and/or extract. The microwave radiation may be configured (e.g., tuned) to break up the large macromolecules in the oil into smaller molecules. For example, microwave radiation, coupled with effects from trace amounts of elements in the vicinity of a well (e.g., silicates, pyrites, phosphates, manganese, nickel, etc.) may catalyze the reaction rates of conversion from heavy oil into lighter (e.g., more liquidous) oil. The microwave radiation may be transmitted into the oil emulsion at block 1230. The resulting lighter oil may be collected at block 1240 by a collection system.

In some embodiments, the composition of the oil may be analyzed at block 1250. For example, the composition of the oil may be analyzed before and/or after refining. Information from the analysis may, in certain embodiments, be fed back to other steps of the method 1200 to adjust, tune, or otherwise affect performance of the step of the method 1200. For example, the information may be fed back to block 1220 or block 1230 to affect the generation and/or transmission of radiation, respectively.

It should be noted that the methods, systems, and devices discussed above are intended merely to be examples. It must be stressed that various embodiments may omit, substitute, or add various procedures or components as appropriate. For instance, it should be appreciated that, in alternative embodiments, the methods may be performed in an order different from that described, and that various steps may be added, omitted, or combined. Also, features described with respect to certain embodiments may be combined in various other embodiments. Different aspects and elements of the embodiments may be combined in a similar manner. Also, it should be emphasized that technology evolves and, thus, many of the elements are examples and should not be interpreted to limit the scope of the invention.

Specific details are given in the description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, well-known processes, algorithms, structures, and techniques have been shown without unnecessary detail in order to avoid obscuring the embodiments.

Merely by way of example, many additions or modifications are possible to any of the oil recovery systems of FIGS. 1, 2, 8, 9, and 10 without departing from embodiments of the invention. For example, additional conduits may be passed from the ground surface to one or more generators and/or other components of the systems for added functionality (e.g., a conduit may provide cool air to cool generator 220 of FIG. 2 during operation).

Also, it is noted that the embodiments may be described as a process which is depicted as a flow diagram or block diagram. Although each may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be rearranged. A process may have additional steps not included in the figure.

Having described several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the invention. For example, the above elements may merely be a component of a larger system, wherein other rules may take precedence over or otherwise modify the application of the invention. Also, a number of steps may be undertaken before, during, or after the above elements are considered. Accordingly, the above description should not be taken as limiting the scope of the invention. 

1. A system for recovering oil from an oil shale deposit, the system comprising: a microwave generation system, adapted to generate microwave radiation substantially at a microwave frequency and substantially at a power level; and a radiation system, operatively coupled with the microwave generation system, and comprising: an antenna, adapted to transmit at least a portion of the microwave radiation at the microwave frequency into the oil shale deposit, wherein the antenna is located within the oil shale deposit and the at least a portion of the microwave radiation is transmitted substantially omni-directionally; and a sheath, adapted to be substantially transparent to the microwave frequency in at least one transmission direction, and adapted to mitigate harmful physical exposure of the antenna to the oil shale deposit and released constituents, wherein the released constituents comprise constituents of the oil shale deposit released during heating as a result of the antenna transmitting at least a portion of the microwave radiation at the microwave frequency into the oil shale deposit, one of the released constituents being released oil.
 2. The system of claim 1, wherein the microwave generation system comprises: a klystron, adapted to generate microwave radiation at the microwave frequency, the microwave frequency being substantially 2.45 to 2.5 GHz.
 3. The system of claim 1, wherein the microwave generation system comprises: a klystron, adapted to generate microwave radiation at the power level, the power level being selected from a group consisting of: substantially one-half megawatt; substantially 100 kilowatt; and substantially 4.5 megawatt.
 4. The system of claim 1, wherein the microwave generation system comprises: a klystron, adapted to generate microwave radiation at the microwave frequency as pulsed-wave radiation.
 5. The system of claim 1, wherein at least a portion of the microwave generation system is located within the oil shale deposit.
 6. The system of claim 1, wherein the radiation system further comprises: a wave guide, operatively coupled with the microwave generation system and the antenna, and adapted to guide the propagation of substantially all of the microwave radiation at the microwave frequency from the microwave generation system to the antenna.
 7. The system of claim 1, wherein the antenna comprises: a rectangular cross-section having two wide faces and two narrow faces; and a plurality of slots penetrating each of the wide faces and adapted to transmit at least a portion of the microwave radiation at the microwave frequency.
 8. The system of claim 1, wherein the radiation system further comprises: a plurality of antennae distributed throughout the oil shale deposit, each of the plurality of antennae being operatively coupled with the microwave generation system, wherein the antenna is one of the plurality of antennae.
 9. The system of claim 1, wherein: the microwave generation system comprises a plurality of microwave generators; and the radiation system further comprises: a plurality of antennae distributed throughout the oil shale deposit, each of the plurality of antennae being operatively coupled with at least one of the microwave generators.
 10. The system of claim 1, wherein the radiation system further comprises: a reflector unit, located substantially within the oil shale deposit and adapted to receive incident microwave radiation in a first direction and transmit at least a portion of the incident microwave radiation in a second direction, the second direction being different from the first direction and oriented towards a portion of the oil shale deposit, wherein the incident microwave radiation comprises a portion of the microwave radiation transmitted by the antenna into the oil shale deposit.
 11. The system of claim 1, wherein the radiation system further comprises: a first reflector unit, located substantially within the oil shale deposit at a first distance from the antenna, and adapted to: be substantially transparent to microwave radiation received in a first direction; and be substantially reflective to microwave radiation received in a second direction; and a second reflector unit, located substantially within the oil shale deposit at a second distance from the antenna, the second distance being greater than the first distance, wherein the second reflector unit is adapted to: be substantially reflective to microwave radiation received in the first direction.
 12. The system of claim 1, further comprising: a power management system, operatively coupled with the microwave generation system, and adapted to manage power supplied to the microwave generation system.
 13. The system of claim 1, further comprising: an oil extraction system, adapted to transport the released constituents from the oil shale deposit to a collection location.
 14. The system of claim 13, further comprising: an oil collection system, adapted to collect the released oil at the collection location.
 15. The system of claim 14, wherein the oil collection system comprises a surface oil collector.
 16. The system of claim 13, wherein the oil extraction system further comprises: piping located in a bore hole bored into the oil shale deposit and adapted to direct the flow of at least a portion of the released constituents toward the collection location.
 17. The system of claim 16, wherein the piping is substantially sealed and comprises a region adapted to allow entry of at least a portion of the released constituents into the pipe through the region.
 18. The system of claim 16, wherein the piping comprises a lower end located substantially at the depth of oil shale deposit, the lower end comprising a seal, wherein the sheath is operatively coupled with the seal at the lower end of the piping and located within the bore hole.
 19. The system of claim 13, further comprising: an oil processing system, adapted to process at least a portion of the released constituents.
 20. The system of claim 15, wherein the oil processing system is further adapted to extract the released oil from the released constituents and to at least partially refine the released oil.
 21. The system of claim 15, further comprising: a power management system, operatively coupled with the microwave generation system, and adapted to manage power supplied to the microwave generation system, wherein the oil processing system comprises a recycling system, adapted to recycle at least a portion of the released constituents for use by the power management system.
 22. The system of claim 1, further comprising: a sensor system, adapted to generate feedback information as a function of at least one environmental condition.
 23. The system of claim 22, wherein the at least one environmental condition relates to at least one of: an amount of the released constituents; a composition of the released constituents; a temperature; or a pressure.
 24. The system of claim 22, wherein the sensor system comprises a plurality of dielectric probes, at least a portion of the dielectric probes being located within the oil shale deposit.
 25. The system of claim 22, wherein the sensor system comprises a millimeter-wave spectrometer, adapted to determine a composition of at least a portion of the released constituents.
 26. The system of claim 22, further comprising: a feedback control system, adapted to: receive feedback information from the sensor system; and make a reconfiguration determination as a function of the feedback information, wherein the reconfiguration determination relates to at least one of: the microwave frequency; the power level; a polarity of the microwave radiation; a direction of propagation of the microwave radiation; a depth of transmission of the microwave radiation; or a location of transmission of the microwave radiation.
 27. A method for recovering oil from an oil shale deposit, the method comprising: generating microwave radiation substantially at a microwave frequency; and transmitting at least a portion of the microwave radiation substantially omni-directionally into the oil shale deposit from an active radiation source located substantially within the oil shale deposit, such that at least a portion of the oil shale deposit heats to a temperature level at which released constituents are released, the released constituents comprising released oil.
 28. The method of claim 27, further comprising: receiving incident microwave radiation in a first direction from a radiation source; and transmitting at least a portion of the incident microwave radiation in a second direction, the second direction being different from the first direction and oriented towards a portion of the oil shale deposit.
 29. The method of claim 28, wherein the incident microwave radiation comprises at least a first portion of the microwave radiation transmitted by the active radiation source, at least a second portion of the microwave radiation transmitted by the active radiation source having been absorbed by a portion of the oil shale deposit.
 30. The method of claim 27, further comprising: transporting at least a portion of the released constituents from the oil shale deposit to a collection location.
 31. The method of claim 27, further comprising: processing at least a portion of the released constituents.
 32. The method of claim 27, further comprising: sensing feedback information as a function of at least one environmental condition; and making a reconfiguration determination as a function of the feedback information, wherein the reconfiguration determination relates to at least one of: the microwave frequency; the power level; a polarity of the microwave radiation; a direction of propagation of the microwave radiation; a depth of transmission of the microwave radiation; or a location of transmission of the microwave radiation.
 33. A method for recovering oil from an oil reservoir site, the method comprising: providing an oil collection system; pumping a measured amount of water into the oil reservoir site, wherein the oil reservoir site is underground and comprises oil; generating microwave radiation substantially at a microwave frequency; and transmitting at least a portion of the microwave radiation into the oil reservoir site from a plurality of active radiation sources located substantially within the oil reservoir site, such that at least a portion of the water heats to a temperature level at which sufficient steam is generated to force the oil into the oil collection system.
 34. The method of claim 33, wherein at least a portion of the plurality of active radiation sources comprises a klystron and an antenna. 